<template>
  <div>
    <div class="goods">
      <div class="menu-wrapper">
        <ul>
          <li class="menu-item" v-for="(good,index) in goods" :key="index" :class="{current: index === currentIndex}"
          @click="clickMenuItem(index)">
            <span class="text bottom-border-1px">
              <img class="icon" :src="good.icon" v-if="good.icon">
              {{good.name}}
            </span>
          </li>
        </ul>
      </div>
      <div class="foods-wrapper">
        <ul ref="foodsUl">
          <li class="food-list-hook" v-for="(good,index) in goods" :key="index">
            <h1 class="title">{{good.name}}</h1>
            <ul>
              <li class="food-item bottom-border-1px" v-for="(food,index) in good.foods" :key="index"
              @click="showFood(food)">
                <div class="icon">
                  <img width="57" height="57"
                       :src="food.icon">
                </div>
                <div class="content">
                  <h2 class="name">{{food.name}}</h2>
                  <p class="desc">{{food.description}}</p>
                  <div class="extra">
                    <span class="count">月售 {{food.sellCount}} 份</span>
                    <span>好评率 {{food.rating}}%</span>
                  </div>
                  <div class="price">
                    <span class="now">¥{{food.price}}</span>
                    <span class="old" v-if="food.oldPrice">¥{{food.oldPrice}}</span>
                  </div>
                  <div class="cartcontrol-wrapper">
                    <CartControl :food="food"/>
                  </div>
                </div>
              </li>
            </ul>
          </li>
        </ul>
      </div>
      <ShopCart />
    </div>
    <Food :food="food" ref="food"/>
  </div>
</template>

<script>
    import Bscroll from 'better-scroll';
    import {mapState} from 'vuex';
    import CartControl from '../../../components/CartControl/CartControl'
    import Food from '../../../components/Food/Food'
    import ShopCart from '../../../components/ShopCart/ShopCart'
    export default {
      data(){
        return {
          scrollY: 0,
          tops: [],
          food: {} //弹窗Food
        }
      },
      mounted() {
        this.$store.dispatch('getShopGoods',() => {
          this.$nextTick(() =>{
           this._initScroll();
           this._initTops();
          })
        });

      },
      methods: {
        _initScroll() {
          //列表显示后在渲染
          new Bscroll('.menu-wrapper',{
            click: true
          });
          this.foodsScroll = new Bscroll('.foods-wrapper',{
            //probeType: 2           //不计算惯性的滑动
            probeType: 3,             //计算惯性的滑动
            click: true
          });
          //给右侧列表绑定scroll监听
          this.foodsScroll.on('scroll',({x,y}) => {
            this.scrollY = Math.abs(y);
          });

          this.foodsScroll.on('scrollEnd',({x,y}) => {
            this.scrollY = Math.abs(y);
          })
        },
        _initTops(){
          const tops = [];
          let top = 0;
          tops.push(top);
          const lis = this.$refs.foodsUl.getElementsByClassName('food-list-hook'); //找到所有分类的li
          Array.prototype.slice.call(lis).forEach( li => {
            top += li.clientHeight;
            tops.push(top);
          })
          this.tops = tops;
        },
        clickMenuItem(index) {
          //得到目标位置的scrollY
          const scrollY = this.tops[index];
          //立即更新左侧的列表样式
          this.scrollY = scrollY;
          this.foodsScroll.scrollTo(0,-scrollY,300)
        },

        //显示点击的food弹框
        showFood(food){
          this.food = food;
          //父组件调用子组件方法，显示food弹框
          this.$refs.food.toggleShow();
        }
      },
      computed: {
        ...mapState(['goods']),
        //计算当前分类的下标
        currentIndex (){
          const {scrollY, tops} = this;
          const index = tops.findIndex((top, index) => {
            return scrollY >= top && scrollY < tops[index+1]
          })
          return index;
        }
      },
      components: {
        CartControl,
        Food,
        ShopCart

      }

    }
</script>

<style lang="stylus" rel="stylesheet/stylus">
  @import "../../../common/stylus/mixins.styl"
  .goods
    display: flex
    position: absolute
    top: 195px
    bottom: 46px
    width: 100%
    background: #fff;
    overflow: hidden
    .menu-wrapper
      flex: 0 0 80px
      width: 80px
      background: #f3f5f7
      .menu-item
        display: table
        height: 54px
        width: 56px
        padding: 0 12px
        line-height: 14px
        &.current
          position: relative
          z-index: 10
          margin-top: -1px
          background: #fff
          color: $green
          font-weight: 700
          .text
            border-none()
        .icon
          display: inline-block
          vertical-align: top
          width: 12px
          height: 12px
          margin-right: 2px
          background-size: 12px 12px
          background-repeat: no-repeat
        .text
          display: table-cell
          width: 56px
          vertical-align: middle
          bottom-border-1px(rgba(7, 17, 27, 0.1))
          font-size: 12px
    .foods-wrapper
      flex: 1
      .title
        padding-left: 14px
        height: 26px
        line-height: 26px
        border-left: 2px solid #d9dde1
        font-size: 12px
        color: rgb(147, 153, 159)
        background: #f3f5f7
        text-align left
      .food-item
        display: flex
        margin: 18px
        padding-bottom: 18px
        bottom-border-1px(rgba(7, 17, 27, 0.1))
        &:last-child
          border-none()
          margin-bottom: 0
        .icon
          flex: 0 0 57px
          margin-right: 10px
        .content
          flex: 1
          text-align left
          .name
            margin: 2px 0 8px 0
            height: 14px
            line-height: 14px
            font-size: 14px
            color: rgb(7, 17, 27)
          .desc, .extra
            line-height: 10px
            font-size: 10px
            color: rgb(147, 153, 159)
          .desc
            line-height: 12px
            margin-bottom: 8px
          .extra
            .count
              margin-right: 12px
          .price
            font-weight: 700
            line-height: 24px
            .now
              margin-right: 8px
              font-size: 14px
              color: rgb(240, 20, 20)
            .old
              text-decoration: line-through
              font-size: 10px
              color: rgb(147, 153, 159)
          .cartcontrol-wrapper
            position: absolute
            right: 0
            bottom: 12px
</style>

